Yep, it was mostly America im sure. The Xbox speaks to the heart of the competitive gamer and everyone knows the most competitive console is the Xbox. Lets see how they do when Sony launches in Japan. Congrats to them. Microsoft is smart they know in order to stay close with Sony in sales they have to front load all their sales in America.
Do you think Microsoft is giving up on the rest of the world?
No. They will focus on everyone else later. Microsoft knew Sony would sell well based on preorders so they wanted front loaded sales. Easiest way to get front loaded sales is to amp up Americans. If they would've spread out their consoles across the world in all the usual places they would've actually sold even less than Sony. They made sure the Xbox wouldn't sell out in America in order to stay as close as possible.